In the last decade, the development of the SEM/EBSD orientation imaging systems leads to various and numerous applications in the field of material science. Similar orientation based microstructure maps can be obtained using TEM. In modern transmission microscopes, the beam can be computer controlled; in association with a recording system like a CCD camera, it is possible to build a fully automatic mapping system. Until recently, however, progress in this direction has been relatively slow. We describe a new orientation mapping system which uses TEM Kikuchi patterns or/and TEM convergent beam electron diffraction patterns. In comparison to SEM/EBSD systems, the TEM based orientation imaging system has a better spatial resolution and a higher accuracy in the orientation determination. As to the scale of the microstructure, the TEM and SEM systems are complementary. Although there are some similarities, the TEM based system we are going to present differs from SEM/EBSD systems in several points. Because the TEM diffraction patterns correspond to a smaller solid angle and the reflecting planes are of higher indices, the indexing procedure needs to be more efficient. The TEM diffraction patterns contain line or/and band contrast. In consequence, the automatic line detection procedure is also slightly different. A recrystallized copper sample is used to illustrate the method.